Secure communication of information provided by encryption techniques is desirable in wireless communication devices, such as pagers, cellular telephones, etc. In these environments, there is a need to minimize the amount of information transmitted to control costs and profitability of systems. When the data to be transmitted is encrypted, it is still desirable to minimize the overall amount of data actually transmitted.
Elliptic curve (EC) cryptography has become particularly useful in the field of wireless communication because it is more efficient both in terms of bandwidth and computation time than other industry public key encryption standards, such as RSA. An EC processor is used to perform the finite field arithmetic operations associated with EC cryptography. The EC processor exchanges encrypted data to be decrypted, and vica versa, with a host device; such as a wireless communication device. The width of the datapath of the EC processor is preferably much greater than the width of the host bus of the host device, in order for the EC processor to be versatile in use.
Accordingly, a system is needed to efficiently manage the exchange of data between the host bus of a host device and an EC processor, particularly when data in the host device and in the EC processor is most efficiently organized and stored in different bit patterns.